1. Field of the Invention
The present invention is generally related to device configuration and method of a tire pressure-sensing (TPS) and low-pressure warning device. More particularly, this invention is related to device configuration and mechanical pressure switch design for implementing a compact tire pressure monitoring to mechanically turning on a light emitting diode (LED) for providing a low pressure warning light when the tire pressure is lower than a threshold pressure.
2. Description of the Related Art
Conventional technologies and devices for measuring the changes of tire pressure are still faced with the difficulties that the tire pressure measurements and warning often require continuously supply of a battery power. A battery has a limited lifetime and the power consumed for continuously monitoring and providing low pressure-warning signals may not be reliable if the capacity of battery is depleted.
Generally there are two types of tire pressure monitoring systems (TPMS). The first type of TPMS is an indirect tire pressure monitoring system that monitoring the changes of tire pressures by monitoring the rotational speed differences as that detected and transmitted through the ABS speed transmitter. This type of TPMS has a limitation that the tire pressure monitoring operation would become ineffective when there are simultaneous tire-pressure changes occur in more than one tires. Also, the TPMS become unreliable when a vehicle is traveling at a speed more than one hundred kilometers per hour. A second type of tire pressure-monitor system is a direct tire pressure monitoring system implemented with tire pressure measurement devices directly mounted on the tire. The tire pressures are measured and monitored continuously. Once the tire pressure in a tire is lower or higher than a threshold value, an alarm signal is generated. The direct type of TPMS has definite advantages of higher accuracy and reliability over the indirect type of TPMS. However, a discussed above, the direct TPMS devices still have limit capability to effectively transmit pressure monitoring signals and furthermore, there still lacks an antitheft device mechanism with the tire pressure monitoring devices directly mounted onto the tires. Practical application of the direct TPMS devices would still have the concerns that such devices may often be stolen and lost due to such limitations.
In order to resolve the power consumption limitation when a battery is implemented in the tire pressure-monitoring device, it generally requires the use of a programmable chip with intelligence built into a controller. Such implementation often leads to a higher production cost of the power-monitoring device. The application of the tire pressure monitoring device and systems become uneconomical due to the higher cost of implementation. The higher price of tire-pressure monitoring and control would often limit the practical marketability and usefulness of such devices and systems.
Therefore, there is still need to design and manufacture a tire pressure monitor device and system with further simplified and convenient to implement devices that would enable those of ordinary skill in the art to overcome such difficulties and limitations.